With respect to a food preservation apparatus provided with high-voltage electric field forming electrodes, conventionally, there has been disclosed a food preservation apparatus which includes a current limiting mechanism in a high voltage power source, a DC current is used as a DC power source, and an AC current is superimposed on the DC current (patent document 1). This apparatus aims at a preservation effect generated by electric field treatment. It is considered that by providing the apparatus where a food support shelf in a freezer or a refrigerator is used as a high-voltage electric field forming electrode, and a high voltage electric field is applied to foods during preservation, foods and the like can be preserved for a long period or an action of improving tastes of foods and the like is generated.
Conventionally, as inventions relating to a positive electric field treatment method, a positive electric field treatment apparatus and electrodes used in these method and apparatus, there has been disclosed the invention where foods and the like are placed on a shelf in a preservation storage, and electricity is applied to a charge plate (patent document 2).